initial code (#6)

* initial code commit

radarr/expression.go

@@ -0,0 +1,47 @@
+package radarr
+
+import (
+	"fmt"
+	"github.com/antonmedv/expr"
+	"github.com/l3uddz/nabarr"
+	"github.com/l3uddz/nabarr/media"
+	"github.com/pkg/errors"
+)
+
+func (c *Client) compileExpressions(filters nabarr.PvrFilters) error {
+	exprEnv := &nabarr.ExprEnv{}
+
+	// compile ignores
+	for _, ignoreExpr := range filters.Ignores {
+		program, err := expr.Compile(ignoreExpr, expr.Env(exprEnv), expr.AsBool())
+		if err != nil {
+			return fmt.Errorf("ignore expression: %v: %w", ignoreExpr, err)
+		}
+
+		c.ignoresExpr = append(c.ignoresExpr, nabarr.NewExprProgram(ignoreExpr, program))
+	}
+
+	return nil
+}
+
+func (c *Client) ShouldIgnore(mediaItem *media.Item) (bool, string, error) {
+	exprItem := nabarr.NewExprEnv(mediaItem)
+
+	for _, expression := range c.ignoresExpr {
+		result, err := expr.Run(expression.Program, exprItem)
+		if err != nil {
+			return true, expression.String(), fmt.Errorf("checking ignore expression: %w", err)
+		}
+
+		expResult, ok := result.(bool)
+		if !ok {
+			return true, expression.String(), errors.New("type assert ignore expression result")
+		}
+
+		if expResult {
+			return true, expression.String(), nil
+		}
+	}
+
+	return false, "", nil
+}